The methods for reusing a polyester as the same type of polyester material include a material cycle and a chemical cycle. In the material cycle, a polyester is softened, for example, by the application of heat and then re-formed. This method of reuse is simple in process construction and involves low recycling costs per cycle. However, since the properties (e.g., moldability) of the original material are deteriorated as the re-forming is repeated, the number of recycles is limited. Moreover, the material must inevitably be changed over to applications having lower property requirements.
On the other hand, the chemical cycle comprises returning a polyester to the form of raw materials, purifying them, and synthesizing a polyester again. Consequently, this method requires a complicated system and involve high recycling costs per cycle. However, it can provide much value added because the number of recycles is markedly increased and the application of the recycled material is not limited.